Value printing die protection mechanism in a postage meter machine

ABSTRACT

A die protection mechanism that prevents the taking of fraudulent, non-metered impressions from the value printing die surface of a postage meter machine. A linkage assembly is pivotally supported adjacent the print wheels of the postage meter machine such that a projecting portion will extend beyond the diameter of the print wheels when the postage meter machine is inoperative, but the linkage assembly will be pivoted during operation for the purpose of allowing the printing of postage on a mail piece. The mechanism is particularly useful in a postage meter having a reciprocating platen.

BACKGROUND OF THE INVENTION

In the field of value printing, as for example in postage metermachines, a constant vigil is maintained to assure that the taking offraudulent impressions from the value printing die surface of a printingmember is prevented. In a reciprocating platen type of postage metermachine, this is of a particular concern since the print head of suchmachines is not rotated out of exposure as occurs with a rotatary typepostage meter machine. One scheme for preventing the taking offraudulent impressions is disclosed in U.S. Pat. No. 2,350,853 wherein amanually operable postage meter machine of the reciprocating type isdisclosed. A rocker member with a plunger portion is utilized to preventfraudulent impression taking. The plunger portion extends within aprinting die block and is normally located beyond the perimeter of theprinting dies. Although such a device functions quite well in amechanical postage meter machine, it obviously would be impractical toadapt it for present day postage meter machines, because of thecompactness and generally automatic functioning of the latter. Theproblem with preventing fraudulent impression taking involves exposureof the print head. The print head may be "wiped" when exposed i.e., anenvelope or tape may be pressed against the print head to obtainunauthorized postage. In considering schemes for preventing suchfraudulent taking of postage, problems arise with postage meter mailingmachines because the print head must be exposed during a period ofoperation and a wrongdoer may stop operation at this particular periodand obtain fraudulent impressions if no safeguards are taken.

SUMMARY OF THE INVENTION

A mechanism has been devised wherein a security feature is provided fora postage meter machine of the reciprocating platen type. In such apostage meter machine, a platen is pivotally mounted in a slot so as tobe driven towards a print head upon a mail piece being inserted into theslot. In the preferred embodiment of this invention, a linkage assemblyis pivotally located adjacent the print wheels of the print head. Thelinkage assembly has a portion that extends beyond the location of theprinting dies when the postage meter machine is at rest so that there isno possibility of the print dies being wiped to obtain fraudulentimpressions.

Upon a mail piece, such as an envelope, being placed into contact with aprint switch located within the slot, the platen will be driven towardthe selected print dies of the print head and the linkage assembly willbe pivoted out of the slot so that an authorized impression may be madeupon the mail piece. Subsequent to the printing of postage, the linkageassembly will be rotated in the opposite direction so that the printhead will no longer be exposed, thereby securing the print head oncemore from unauthorized impression taking.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a cross sectional, partially schematic view of a postage metermachine in which the instant invention is utilized; and

FIG. 2 is the same view as shown in FIG. 1 with the postage metermachine in a different stage of operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawing, a print station of a postage meter machineis generally shown at 10 and is located within the housing 12 of themachine. A shaft 14 is mounted within the housing 12 and rotatablysupports a plurality of print wheels 16. The normal number of printwheels is four although it will be appreciated the number may vary. Eachof the print wheels 16 has a plurality of print dies 18 located aboutthe perimeter thereof each print die representing one numeral from 0-9,respectively. A gear 20 is connected to each of the print wheels 16 soas to allow the selective rotation of the print wheels for printingselected postage as is well known in the art.

A portion of the postage meter machine housing 12 forms a slot 22 thathas a switch 23 therein. Located at the upper part of the slot 22 is anindicia plate 24 that has an opening 26 therein through which openingthe selected print dies 18 are located. On the other lower part of theslot 22 is a deck 28 that has an opening 30 therein. Received within theopening 30 is a platen 32 that is mounted for reciprocal movement. Thismovement is occasioned by pins 34 (only one being shown) mounted onopposite ends of the platen 32 which pins are received within pivot arms36. The pivot arms 36 are mounted on a shaft 37 for rotation therewith,the shaft being rotatably mounted in the housing 12.

A shaft 38 is supported within the housing 12 and mounts a bracket orlinkage assembly 40 for pivotal movement thereabout. The linkageassembly 40 has a plurality of links 42 each link being associated witha print wheel 16. Each of the links 42 has a dependent portion 44 thatis received within the opening 26 of the indicia plate 24. Opposite thedepending portion 44 is a rack 46 on each of the links 42 that areoperative to mesh with the gear 20 of its associated print wheel 16. Atension spring 48 is connected at one of its ends to the linkageassembly 40 and its other end is mounted on the housing 12. A shaft 50is rotatably supported within the housing 12 and has a pivot 52 securedthereto for rotation therewith. A finger 54 extends from the rectifierbracket 40 and is engaged by the pivot 52. A motor M is located withinthe housing 12 to provide drive to the linkage assembly 40 and to thepivot arms 36 through a cam 56.

As is shown in FIG. 2, when the print station 10 is not in the act ofprinting, the depending portions 44 of the linkage assembly 40 will bereceived within the opening 26 and extend below the level of the indiciaplate 24 so that the depending portions are located beyond the printdies 18 located on the perimeter of the print wheels 16 as well asbeyond the surface of the indicia plate 24, thereby preventing the printwheels and indicia plate from being "wiped". The depending portions 44act as a physical barrier preventing the taking of unauthorizedimpressions. During the printing operation, which is initiated by a mailpiece 58, such as an envelope, engaging the switch 23, the shaft 50 isrotated in a clockwise direction, as seen in FIG. 1, so that the pivot52 is moved away from the finger 54. With this event, the tension spring48 pivots the linkage assembly 40 about the shaft 38 to push the racks42 into engagement with the gears 20 of the print wheels 16. In thisposition, the depending portions 44 are lifted away from the platen 32so that they no longer extend beyond the print dies 18 and the racks 46engage the gear 20 teeth to rectify and lock the print wheels 16. Asthis occurs, the pivot arms 36 will be pivoted by the cam 56 to lift theplaten 32 into the printing engagement with the indicia plate 24 and theprint wheels 16 to make an impression upon the mail piece that had beeninserted into the slot 22.

After the printing of postage has been completed, the shaft 50 will berotated in the counterclockwise direction as seen in FIG. 2 and thepivot 52 will engage the finger 54 to overcome the spring 48. With thisoccurring, the linkage assembly 40 will pivot in the counterclockwisedirection about the shaft 38 so that the depending portions 44 aredriven towards the platen 32 and into the space 26 to a location beyondthe perimeter of the print wheels 16, including the print dies 18, andbeyond the surface of the indicia plate 24. In this blocking position,one would be prevented from placing an object into complete contact withthe print wheels 16 and the indicia plate 24. As a consequence, only apartial impression would be obtained which could not serve as postage.

As will be readily appreciated, what has been provided is a mechanismwhich not only prevents the unauthorized taking of impressions but alsoacts to secure the print wheels for proper registration during theprinting operation through the meshing of the racks 46 with the gear 20teeth.

What is claimed is:
 1. A mechanism for preventing the taking offraudulent impressions from the print wheels of a postage meter machinethat has settable print wheels, a reciprocating platen operative to bemoved into contact with the print wheels, means for reciprocally drivingthe platen into and out of printing contact with the print wheels, aprint switch for sensing upon the platen the presence of a mail piece tobe imprinted and to activate a driving means to drive the platen intoand out of contact with the print wheels, comprising: linkage meanspivotally supported within the machine adjacent the print wheels, saidlinkage means having a portion that extends intermediate the printwheels and the platen when said linkage means is in a first position,means for moving said linkage means upon the print switch being enabledto a second position wherein said portion is moved away from a positionbetween the print wheels and the platen and means for returning thelinkage means to said first position upon the platen being driven intoand out of contact with the print wheels by the driving means.
 2. Amechanism for preventing fraudulent impressions being obtained from theprint wheels of a reciprocating type of postage meter machine that hasprint wheels settable through gears integral therewith, a reciprocatingplaten operative to be moved into contact with the print wheels, drivemeans for reciprocally driving the platen into and out of contact withthe print wheels, a print switch for sensing the presence of a mailpiece to be imprinted upon the platen and activating the drive means toaffect a print cycle by driving the platen into contact with the printwheels upon actuation of the print switch, comprising: a bracketpivotally supported within the machine and having a plurality of linkseach of which is adjacent a print wheel, said bracket having anextending portion, said extending portion being located intermediate theprint wheels and the platen when in a first position, the drive meansbeing operative to move said bracket to a second position such that saidextending portion is moved away from a position between the print wheelsand the platen upon the power switch being enabled, said bracketengaging the gears of the print wheels to secure the print wheels, and ameans for returning the rectifier bracket to said first position uponthe platen being driven out of print contact with the print wheelswhereby said bracket will become disengaged from the gears of the printwheels.
 3. A method of preventing the taking of fraudulent impressionsfrom the print wheels of a postage meter machine that has settable printwheels, a reciprocating platen operative to be moved into printingcontact with the print wheels, and a print switch for sensing thepresence of a mail piece upon the platen, the steps comprising: placinga linkage assembly within the machine at a first position such that aportion of the linkage assembly extends intermediate the print wheelsand the platen, placing a mail piece into contact with the print switch,moving the linkage assembly to a second position such that the linkageassembly portion is moved away from a position between the print wheelsand the platen, driving the platen into printing contact with the printwheels, driving the platen away from the print wheels, and returning thelinkage assembly to its first position as the platen is driven away fromthe print wheels.
 4. A method of preventing the taking of fraudulentimpressions from the print wheels of a postage meter machine that hassettable print wheels having gears connected thereto, a reciprocatingplaten operative to be moved into printing contact with the print wheelsand, a print switch for activating a print cycle, the steps comprising:placing a linkage assembly within the postage meter machine at a firstposition such that a first portion of the bracket extends intermediatethe print wheels and the platen, activating the print switch to initiatea print cycle, moving the linkage assembly to a second position suchthat its first portion is moved away from a position between the printwheels and the platen and a second portion of the linkage assemblycontacts the print wheel gears to lock the print wheels, reciprocallydriving the platen into printing contact with the print wheels, drivingthe platen away from the print wheels, and returning the linkageassembly to its first position as the platen is driven away from theprint wheels.
 5. A method of preventing the taking of fraudulentimpressions from a postage meter machine that has settable print wheels,a reciprocating platen operative to be moved into printing contact withthe print wheels and a print switch for initiating a print cycle, thesteps comprising: placing a blocking member in a position intermediatethe print wheels and the platen, actuating the print switch, removingthe blocking member from the intermediate position, locking the printwheels, driving the platen into printing contact with the print wheels,driving the platen away from the print wheels, and returning theblocking member to the intermediate position as the platen is drivenaway from the print wheels.
 6. A method of preventing the taking offraudulent impressions from a postage meter machine that has settableprint wheels, a reciprocating platen operative to be moved into printingcontact with the print wheels and a print switch for initiating a printcycle, the steps comprising: placing a blocking member in a positionintermediate the print wheels and the platen, actuating the printswitch, removing the barrier from the intermediate position, locking theprint wheels, driving the platen into printing contact with the printwheels, driving the platen away from the print wheels, returning theblocking member to the intermediate position and unlocking the printwheels as the platen is driven away from the print wheels.